As devices operating by using electric power increase, usage of batteries has also increased. Recently, as mobile devices such as mobile phones, robot vacuum cleaners, etc. have been widely used, batteries storing electric power have been emphasized.
Since there is a limitation in storage capacity of a battery, a battery mounted in a device has to be charged or replaced before or after the battery is discharged. Since it takes a predetermined time period to charge a battery, the battery may be replaced if the device has to be used immediately.
In general, when a battery is replaced, power supply from the battery is stopped, and thus, the device is also turned off. In this case, when the device is turned on after replacing the battery, the device has to reboot if the device requires a rebooting operation, and then, the device may not be used for the time period taken to perform the rebooting, and operating efficiency degrades.
Korean Patent Publication No. 2004-0026515 discloses a portable wireless terminal having a locking device allowing a battery pack to be detached.